If the personal prizes are staying the same, the team prizes will, by definition, be generous, as many teams do the requirements as is, they’re just encouraging the middle and lower performers to do well by using peer pressure.
Also to reiterate what has been said already, I think it’s a really good idea to have a persons score be above zero before they can claim team prizes, but that’s as far as it should go. Else, it causes problems (both for pg and the players) on getting the minimum requirement for each prize right, and it essentially creates a second personal prize category, versus a team prize category.
As mike said:
In summary, event score > 0 is good! Making sigils and prizes harder to get for your teammates? Bad.